Thermal probe assembly with mold-over crimp sensor packaging

Abstract

The present invention generally includes a thermal sensor assembly for a vehicle application including an insert molded part having a thermistor/wire sub-assembly and terminal that are assembled with a "F" crimp and resistance welded that are insert molded to a pre-mold or connector that has a shut-off plate seal on the terminal's insulation crimp. The invention provides a more robust package that is resistant to vibration, insulates the terminals from shorting and permits further handling of the sub-assembly without damage to the terminals. Further, the thermistor can be very small and a very small wire can be used to connect the terminal to the thermistor element. Because a smaller thermistor can be utilized, a much smaller probe tip can be design into the thermal sensor assembly. The insert molded part can either be a preform for press-fit applications or a male sensor connector for applications requiring a metal housing. The pre-molded plastic protects the terminals from short circuiting to the sensor shell or other terminal.

What is claimed is: 
     
       1. A thermal sensor comprising: a thermistor and a pair of wires leading therefrom, each wire having an insulation covering a portion thereof so that one end of the wire is exposed, a male terminal for each wire, the male terminal having a metal crimp having a first finger crimped to the insulation covering the wire and a second finger crimped to the exposed end of the wire, and wherein the exposed end of the wire is resistance welded to the crimp;   a pre-mold sealing off on the first finger and encapsulating the second finger, the resistance weld, and only a portion of the first finger leaving a portion exposed.   
     
     
       2. A thermal sensor as set forth in claim 1 further comprising a metal housing secured to the pre-mold and surrounding the thermistor, and wherein the pre-mold further encapsulates a portion of each wire and a portion of each terminal so as to isolate the respective portions of each wire and terminal from each other and from the metal housing. 
     
     
       3. A thermal sensor as set forth in claim 1 further comprising a plastic housing secured to the pre-mold and surrounding the thermistor.